This project provides central histopathologic services for all other projects in this application. Gastric biopsies from patients in Columbia and New Orleans will be processed and interpreted by the team of pathologists shown below. A global diagnosis based on previously defined criteria will be assigned to each case. Additionally, special histopathologic studies will be carried out to provide more detailed information from each patient: a) detailed protocol gradings for acute as well as chronic inflammation, gland neck hyperplasia, atrophy (gland loss), small intestinal and/or colonic metaplasia and dysplasia (low vs high grade); b) nucleolar organizer regions (silver NORs); c) PCN/cyclin monoclonal antibody; d) connective tissue stain to evaluate the degree of fibrosis; e) pepsinogens I and II; f) mucins: PAS Alcian-Blue and HID- Alcian Blue stains. Numerical grades for each morphological parameter will be assigned by the pathologist while blinded as to the identity of the patient. It is expected that the qualitative (global diagnosis) and quantitative parameters will provide the basic information needed to evaluate the hypotheses postulated in the other projects, namely chemoprevention, in vivo nitrosation and helicobacter infection. The morphologic evaluation will also be correlated with the molecular genetic abnormalities, providing evidence to evaluate the timing of genetic injuries in the causal chain.